Self-Body Image Acquisition and Posture Generation with Redundancy using Musculoskeletal Humanoid Shoulder Complex for Object Manipulation

TL;DR

This paper introduces a novel method for learning a musculoskeletal humanoid's body image and generating postures using inverse kinematics with shoulder complex redundancy, demonstrated through automobile steering wheel operation.

Contribution

It develops a self-body image acquisition method and posture generation approach utilizing shoulder joint redundancy based on scapulohumeral rhythm, enhancing humanoid manipulation capabilities.

Findings

Successfully operated a car steering wheel using the proposed method.

Enhanced shoulder joint redundancy with deep muscles and stabilization.

Validated effectiveness through experiments with the Kengoro humanoid.

Abstract

We proposed a method for learning the actual body image of a musculoskeletal humanoid for posture generation and object manipulation using inverse kinematics with redundancy in the shoulder complex. The effectiveness of this method was confirmed by realizing automobile steering wheel operation. The shoulder complex has a scapula that glides over the rib cage and an open spherical joint, and is supported by numerous muscle groups, enabling a wide range of motion. As a development of the human mimetic shoulder complex, we have increased the muscle redundancy by implementing deep muscles and stabilize the joint drive. As a posture generation method to utilize the joint redundancy of the shoulder complex, we consider inverse kinematics based on the scapular drive strategy suggested by the scapulohumeral rhythm of the human body. In order to control a complex robot imitating a human body, it is essential to learn its own body image, but it is difficult to know its own state accurately due to its deformation which is difficult to measure. To solve this problem, we developed a method to acquire a self-body image that can be updated appropriately by recognizing the hand position relative to an object for the purpose of object manipulation. We apply the above methods to a full-body musculoskeletal humanoid, Kengoro, and confirm its effectiveness by conducting an experiment to operate a car steering wheel, which requires the appropriate use of both arms.